I had the honor of visiting 3D last night for a message on Leviticus.
Why Leviticus? Short answer - it's part of God's Word and 3D believes in honoring God and His Word. Huzzah!!!
Longer answer - if you step back and look at the larger message and don't get lost in the details, Leviticus gives a very clear picture of a Holy God who demands payment for sin. God wanted His people to be in good standing with Him and with each other. So He gave them what are actually very practical ways to do that.
For example (bonus blog-only tidbit!), many of the Levitical laws concerning general cleanliness created a culture that was much more resistant to disease - thousands of years before germs and bacteria and viruses were discovered! During the Black Plague, Jews were wrongly accused of poisoning Christians with the plauge because many of the Jewish communities were much less affected - simply because they followed what are now considered basic hygenic principles.
Jesus takes the Levitical laws and challenges Christians to go deeper - to not just maintain outward cleanliness or holiness but to look within and deal with thoughts, emotions, and feelings and let a Holy God sanctify what is not right. And because Jesus knew we would fail to perfectly meet the outward -let alone the inward- requirements of the Law, He became the perfect once for all sacrifice to reconcile us to God.